In conventional vehicles, an airbag for protecting the driver is generally mounted in the steering wheel. This type of airbag is also referred to as a “steering wheel airbag.” In the event of a collision, the steering wheel airbag is triggered and is intended to prevent the driver's head from striking the steering wheel. The airbag is supported on the steering wheel and moves toward the driver. Strong accelerations occur during the triggering, in particular in the area directly at the steering wheel. Articles or objects situated on the steering wheel may then be dangerously hurled through the interior of the vehicle. There are similar airbag systems for the front passenger, in which the airbag emerges from the dashboard. However, for the front passenger airbag there are already approaches in which the airbag is situated at the roof frame of the vehicle and which when triggered opens along the windshield, supported on the dashboard and the windshield, and then moves toward the front passenger. This type of airbag is also referred to as a “roof airbag.”
In future highly automated vehicles, the aim is not only to reduce traffic accidents, but in particular also to increase the driving comfort. The driver gives the driving task to a robot driver or a system that may make driving decisions, and the driver may pursue other activities. Thus, in automated driving operation the driver may, for example, read a book or operate a mobile device such as a mobile telephone, a laptop, etc. In a normal working position which the driver would like to assume in the automated driving operation, such objects would be situated between the steering wheel airbag and the driver's head. In the event of an accident and an expanding steering wheel airbag, such objects may endanger the driver, or as “ricochets,” also other occupants. To provide more space for the driver, adjustable steering wheels, for example, may be used in such vehicles. Thus, the steering wheel may be pushed, for example, into a stored position in the middle of the dashboard or into a receptacle in the dashboard to provide the driver with more space during the automated driving operation. The driver thus obtains more room immediately in front of him/her. Consequently, in addition to the steering wheel airbag, a roof airbag may also be used for protecting the driver.
A method and a device for protecting vehicle occupants are described in German Patent Application No. DE 10 2005 001 177 A1, which include a sensor that responds to a side impact event and/or a rollover event in order to generate a collision event signal. A first occupant protection device is inflatable into a first position situated next to a corresponding vehicle seat. A second first occupant protection device is inflatable into a second position situated in front of the corresponding vehicle seat. A control device responds to the collision event signal and immediately activates the inflation of the first occupant protection device. After a predetermined time period elapses following the inflation of the first occupant protection device, the control device activates the inflation of the second occupant protection device.